What is the pressure (in atmospheres) of the sample of gas trapped in the closed-tube mercury manometer shown below if h = 23.6 cm
A) 0.211 atm
B) 0.311 atm
C) 0.411atm
D) 0.511atm
E) None of the above

Question

What is the pressure (in atmospheres) of the sample of gas trapped in the closed-tube mercury manometer shown below if h = 23.6 cm 
A) 0.211 atm 
B) 0.311 atm 
C) 0.411atm 
D) 0.511atm 
E) None of the above

Quizplus · Accepted Answer

We can use the following formula to calculate the pressure of the gas:

P_gas = P_atm + (h/13.6)

Where P_atm is the atmospheric pressure (which we assume to be 1 atm), h is the height difference between the two arms of the manometer, and 13.6 is the density of mercury in g/cm^3.

Plugging in the values, we get:

P_gas = 1 atm + (23.6 cm /13.6 cm/g)

P_gas = 1.73 atm

However, we need to remember that the pressure of the gas is balanced by the pressure of the mercury column in the other arm. Since the mercury level is higher on the left side of the manometer, we need to subtract the difference in height between the two arms:

P_gas = 1.73 atm - (23.6 cm / 13.6 cm/g)

P_gas = 0.311 atm

Therefore, the pressure of the gas trapped in the manometer is 0.311 atm, which corresponds to choice B.

What Is the Pressure (In Atmospheres) of the Sample of Gas